CERTAIN ELEMENTS IN NURSERY PRACTICE 173 



greenhouse bench or a garden, whether the plants are orchids 

 or ferns or raspberries, and whether for one's own use or for 

 sale. In North America, the growing of fruit-trees is sup- 

 posed to be the chief concern of a nursery. We have had a 

 continent to transform into orchards. 



Present practice in North American nurseries is to use heavy 

 machinery and implements for major operations. The me- 

 chanical tractor is used for 

 road work and sometimes 

 in fitting the land. Heavy 

 soil-cutting tools are em- 

 ployed (Plate XI). Over- 

 row tillage is facilitated by 

 wheel cultivators (Plate 

 IV). A mechanical peach- 

 pit planter is invented. 

 Root-grafts are wrapped 

 by machines (Plate V). 

 Leaf-hoppers are captured 



OH horse-drawn devices. FIG 20fl The Stark tree-digger. 



The tree-diggers are now 



of many kinds, and the old hand-digging by means of the 

 long spades is a thing of the past in the large-area fruit-tree 

 plantations. They are drawn by several teams of horses or 

 mules, and sometimes by wire cables pulled by stationary 

 engines. Two of the tree plows are shown in Figs. 199 and 

 200, and again in Plate XI. Two forms of tree-diggers used 

 in the United States Forest Service (Bull. 479) are illustrated 

 in Figs. 201, 202. 



Nursery lands in relation to propagation 



The best land for general nursery purposes is heavy rather 

 than light, containing a good percentage of clay beneath, 



